I've never seen a directional pellet. Then again, I haven't shot my pellet gun in decades. In fact, I have no idea where the darn thing is at!
I have never shot one. It's also very hard to get information on hunting Turkeys with a pellet gun. Pellet guns are allowed to use lead pellets, and that's what I used in the past. I have a couple boxes of 500 pellets.
An air rifle with CO2 would be useful, IMO, as the Sheridan can only load one pellet at a time, then you have to pump the cylinder.
I have only one experience with the Sheridan. I was pretty young, somewhere between 5-10 years old. It started out as a "Betcha can't...", me and the local gunsmith's son had in the alley of our stores. There was a pigeon on the top of this brick building...it was about 20-30 yards, where the pigeon was. David missed, and I followed up with a miss. We would take turns with 1 pellet. My 2nd pellet had some feather explosion, but it gets better...David made me promise I wouldn't tell his dad, cause he was only supposed to be shooting a target on the wall of our liquor store, pigeons were not on the menu. We put the rifle away and I went back to the liquor store...the liquor store had living quarters over the top of it, that used to be common in those days...and one of the kids from upstairs brought the pigeon in with the bone sticking out the side, if anyone lost a pigeon...yes, he was being a smart @$$, but it emphasizes the lesson of not leaving wounded game in the field.
+1 for lessons...+2 for game taken by me as a kid...rabbits in the Victorville desert, and a pigeon in Lynwood.
Interesting looking pellets. They sure pump them up on the tin...I watched a Polymag video on YT, they showed a huge cavity on clay...devastating...but it was 25 cal, and that one is 26 grains. Mine is only 13 grains. The exit wound was bigger than a turkey head. One would need to be accurate enough to get the point inside the meat of the head, if that poly tip can grab some skin, it's game over on that turkey.
Appears I would need an upland game bird tag, and it would need to be in season, but best I can tell it would be legal. I think these pellets are lead under the poly.
My Step-Dad used to use this for shooting ground hogs in his backyard in Westlake, CA. He's long passed...
I don't think it will be easy, and will require getting the rifle dialed in.